Semiconductor apparatus and fabrication method of the same

ABSTRACT

It is an object of the present invention to provide a semiconductor device capable of preventing deterioration due to penetration of moisture or oxygen, for example, a light-emitting apparatus having an organic light-emitting device that is formed over a plastic substrate, and a liquid crystal display apparatus using a plastic substrate. According to the present invention, devices formed on a glass substrate or a quartz substrate (a TFT, a light-emitting device having an organic compound, a liquid crystal device, a memory device, a thin-film diode, a pin-junction silicon photoelectric converter, a silicon resistance element, or the like) are separated from the substrate, and transferred to a plastic substrate having high thermal conductivity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/364,361, filed Feb. 2, 2012, now allowed, which is continuation ofU.S. application Ser. No. 13/010,962, filed Jan. 21, 2011, now U.S. Pat.No. 8,134,153, which is a continuation of U.S. application Ser. No.12/370,767, filed Feb. 13, 2009, now U.S. Pat. No. 8,013,335, which is acontinuation of U.S. application Ser. No. 11/206,000, filed Aug. 18,2005, now U.S. Pat. No. 7,495,256, which is a divisional of U.S.application Ser. No. 10/685,398, filed Oct. 16, 2003, now U.S. Pat. No.7,067,392, which claims the benefit of a foreign priority applicationfiled in Japan as Serial No. 2002-305084 on Oct. 18, 2002, all of whichare incorporated by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a semiconductor apparatus comprising acircuit composed of a device as typified by a thin film transistor(hereinafter, TFT) that is formed by means of bonding a release layer toa substrate to be transferred thereto and a method for manufacturing thesemiconductor apparatus. The present invention relates, for example, toan electrooptical device such as a liquid crystal module, a lightemitting apparatus such as an EL module, and an electric applianceinstalled with such apparatus as its components. In addition, thepresent invention relates to a peeling method of a device andtransferring method of the device to a plastic substrate.

As used herein, the term “semiconductor device” refers to any device asa whole that operates by utilizing semiconductor characteristics. Anelectrooptical device, a light emitting apparatus, a semiconductorcircuit, and an electric appliance are all included in the semiconductordevice.

2. Background Art

Recently, attention has been paid to technology of composing a thin filmtransistor (TFT) using a semiconductor thin film (the thickness of aboutseveral to several hundreds nm) formed on a substrate having aninsulating surface. The thin film transistor is widely applied toelectronic devices such as IC, an electrooptical device, or the like.Especially, the development of the thin film transistor as a switchingelement for an image display apparatus has been quickened.

A variety of applications of such an image display apparatus have beenexpected, above all, utilization of the image display apparatus formobile devices draws attention. Although a glass substrate, a quartzsubstrate, or the like is used in many image display apparatuses atpresent, it has disadvantages that they are easy to crack and heavy.Further, the glass substrate, the quartz substrate, or the like isunsuitable for mass production since it is difficult to be enlarged.Therefore, a TFT device has been attempted to be formed over a substratehaving flexibility as typified by a flexible plastic film.

However, since the heat resistance of the plastic film is low, thehighest temperature during process is required to be low, consequently,it is impossible at present to form the TFT that has high electriccharacteristics compared with the one being formed over a glasssubstrate. Hence, no high-performance liquid crystal display apparatusand light-emitting device using a plastic film has been realized.

If a light-emitting apparatus or a liquid crystal display device inwhich organic light-emitting device (OLED) is formed on a flexiblesubstrate such as a plastic film or the like can be manufactured, thelight-emitting apparatus or the liquid crystal display apparatus can bemanufactured to have a thin thickness and light-weight and applied to acurved surface display, a show window, or the like. Thus, itsutilization is not limited to a cellular phone and its application rangeis extremely wide.

However, in general, a substrate formed of plastic penetrates easilymoisture or oxygen. An organic light-emitting layer is deteriorated dueto these impurities, so that lifetime of a light-emitting apparatusbecomes reduced. Therefore, moisture or oxygen is prevented frompenetrating into the organic light-emitting layer by interposing aninsulating film such as a silicon nitride, silicon oxynitride, or thelike between the plastic substrate and an organic light-emitting deviceconventionally.

In addition, a substrate such as plastic films or the like is weakagainst heat generally. In case of increasing the deposition temperaturefor an insulating film such as silicon nitride, silicon nitroxide, orthe like, a substrate becomes easily deformed. Further, too lowdeposition temperature causes decline in quality of the film anddifficulty of preventing penetration of moisture or oxygen into alight-emitting device. There is also a problem of deforming anddeterioration of a part of a substrate due to localized heat generationduring driving of the device that is formed over a substrate such asplastic films or the like.

DISCLOSURE OF INVENTION

In view of the foregoing, it is an object of the present invention toprovide a semiconductor apparatus capable of preventing deteriorationdue to penetration of moisture or oxygen, for example, a light-emittingapparatus having an organic light-emitting device that is formed over aplastic substrate, and a liquid crystal display apparatus using aplastic substrate.

According to the present invention, devices formed on a glass substrateor a quartz substrate (a TFT, a light-emitting device containing anorganic compound, a liquid crystal device, a memory device, a thin-filmdiode, a pin-junction silicon photoelectric converter, a siliconresistance element, or the like) are separated from the substrate, andtransferred to a plastic substrate having high thermal conductivity. Thepresent invention provides a device of long lifetime by radiating heatgenerated in the device through the plastic substrate having highthermal conductivity.

A plastic substrate having high thermal conductivity is formed of highlythermal conductive resin which is a mixture of metal powder such ascopper, iron, aluminum, or the like; metal fibers; low-melting metals(lead-free solders such as tin, bismuth, and zinc); ceramics such asboron nitride, aluminum boron, magnesium oxide, beryllium oxide, or thelike; and synthetic resin composed of polypropylene, polypropylenesulfide, polycarbonate, polyetherimide, polyphenylene sulfide,polyphenylene oxide, polysulfone, or polyphthalamide. A thermalconductivity of the highly thermal conductive resin is ranging from 2 to30 W/mK.

When ceramics and lead-free solders are mixed into synthetic resin,solder becomes melting by heat generated during injection molding, andcooled down, then hardened, and then, the solder is connected with eachother like a network through scattered ceramics particles. Consequently,effects of thermal conductivity can be more increased.

Specified quantity of ceramics and lead-free solders are mixed to thehighly thermal conductive resin and pelletized. The resulted pellets maybe formed into a plate to obtain a substrate by injection moldingprocess. The substrate is formed to be a plate here, but notexclusively, various shapes of substrate can be formed.

A plastic substrate having high thermal conductivity can achieve thermalconductivity as high as that of metals (titanium, alloy of aluminum,alloy of magnesium, or the lire). In addition, the plastic substrate canbe made at low-cost and formed into light-weight compared with a metalsubstrate.

In the case that the transmittance of a plastic substrate having highthermal conductivity is low, the plastic substrate having high thermalconductivity is used for the substrate provided at non-display sidesince it is necessary that the substrate provided at a display side istransparent to light. Specifically, it is preferable that the plasticsubstrate having high thermal conductivity be provided at a shortdistance from a device that generates heat.

The structure disclosed in this specification is that a semiconductorapparatus comprising:

a plastic substrate or a plastic base material each of which has thermalconductivity as a support medium;

an adhesive in contact with the plastic substrate or the plastic basematerial; and a device over an insulating film in contact with theadhesive.

In the above-described structure, wherein the device is a thin-filmtransistor, a light-emitting device including a light-emitting layercontaining an organic compound, a liquid crystal device, a memorydevice, a pin-junction silicon photoelectric converter, or a siliconresistance element.

In each above-described structure, the adhesive has thermalconductivity. It is preferable that the adhesive for bonding a plasticsubstrate having high thermal conductivity have high thermalconductivity and be thick. For example, an adhesive (insulating thermalconductivity adhesive) containing filler or powder composed of silver,nickel, aluminum, aluminum nitride, or the like is useful.

In each above-described structure, wherein each the plastic substrate orthe plastic base material has higher thermal conductivity than that ofthe adhesive. The plastic substrate or the plastic base material each ofwhich has thermal conductivity is formed of a mixture of low-meltingmetals, ceramics, and synthetic resin composed of polypropylene,polypropylene sulfide, polycarbonate, polyetherimide, polyphenylenesulfide, polyphenylene oxide, polysulfone, or polyphthalamide.

The way of peeling or transferring is not particularly limited. Arelease layer and a substrate may be separated by following, that is; aseparation layer is provided between the release layer and thesubstrate, and the separation layer is removed with etchant; or aseparation layer formed of amorphous silicon (or polysilicon) isprovided between the release layer and the substrate, and separationlayer is exposed to laser beam through the substrate to release hydrogenin the amorphous silicon, and then, space is formed in the separationlayer. In case of using the laser beam, it is preferable that a deviceincluded in a release layer be heated at not more than 410° C. for notreleasing hydrogen in the amorphous silicon before peeling process.

In addition to the above-described ways, a stress peel-off method thatutilize the membrane stress between two films can be used. According tothe peeling-off method, a metal layer, preferably, a metal nitride layeris formed on a substrate, and an oxide layer is formed on the metalnitride layer, then, a device can be formed over the oxide layer, andthen, a deposition process and heating treatment at not less than 500°C. can be carried out without generating peeling, consequently, insidelayers or boundary faces of the oxide layer can be easily separated by aphysical means. In addition, heat treatment or laser irradiation can becarried out before peeling by the physical means in order tofacilitating the peeling.

The present invention also provides a novel method for manufacturing asemiconductor apparatus using a peeling method and a transferringmethod.

In the first structure of the present invention disclosed in thisspecification, a method for manufacturing a semiconductor apparatuscomprises the steps of:

a first process for forming a release layer including a semiconductordevice over a first substrate;

a second process for coating an organic resin film that melts withsolvent over the release layer;

a third process for bonding a second substrate to the organic resin filmwith a first two-sided tape to sandwich the release layer and theorganic resin film between the first substrate and the second substrate;

a fourth process for bonding a third substrate to the first substratewith a second two-sided tape;

a fifth process for separating the first substrate to which the thirdsubstrate is bonded from the release layer by a physical means;

a sixth process for bonding a fourth substrate to the release layer tosandwich the release layer between the second substrate and the fourthsubstrate;

a seventh process for separating the release layer and the firsttwo-sided tape from the second substrate;

an eighth process for separating the release layer from the firsttwo-sided tape; and

a ninth process for removing the organic resin film with solvent.

The organic resin film that melts with solvent is formed on the releaselayer to protect and flatten the surface of a first electrode (an anodeor a cathode for a light-emitting device). Flattening the surface canimprove the adhesiveness of the substrate and the release layer. Formingthe organic resin film on the release layer can improve the adhesivenessof the substrate and the release layer since irregularities due towirings is covered by the organic resin film. The adhesiveness of theother side of the release layer and the substrate can also be improvedwithout adverse effects of irregularities due to wirings.

In the second structure of the present invention, a method formanufacturing a semiconductor apparatus comprises the steps of:

a first process for forming a release layer including a semiconductordevice over a first substrate;

a second process for coating an organic resin film that melts withsolvent over the release layer;

a third process for bonding a second substrate to the organic resin filmwith a first two-sided tape to sandwich the release layer and theorganic resin film between the first substrate and the second substrate;

a fourth process for bonding a third substrate to the first substratewith the second two-sided tape;

a fifth process for separating the first substrate to which the thirdsubstrate is bonded from the release layer by a physical means;

a sixth process for bonding a fourth substrate to the release layer tosandwich the release layer between the second substrate and the fourthsubstrate;

a seventh process for separating the release layer and first two-sidedtape from the second substrate;

an eighth process for separating the release layer from the firsttwo-sided tape;

a ninth process for removing the organic resin film with solvent; and

a tenth process for bonding a fifth substrate to the release layer witha second adhesive to sandwich the release layer between the fourthsubstrate and the fifth substrate.

In the third structure of the present invention, a method formanufacturing a semiconductor apparatus comprises the steps of:

a first process for faulting a release layer including a TFT on a firstsubstrate;

a second process for coating an organic resin film that melts withsolvent on the release layer;

a third process for bonding a second substrate to the organic resin filmwith a first two-sided tape to sandwich the release layer and theorganic resin film between the first substrate and the second substrate;

a fourth process for bonding a third substrate to the first substratewith the second two-sided tape;

a fifth process for separating the first substrate to which the thirdsubstrate is bonded from the release layer by a physical means;

a sixth process for bonding a fourth substrate to the release layer witha first adhesive to sandwich the release layer between the secondsubstrate and the fourth substrate;

a seventh process for separating the release layer and the firsttwo-sided tape from the second substrate;

an eighth process for separating the release layer from the firsttwo-sided tape;

a ninth process for removing the organic resin film with solvent;

a tenth process for fabricating a light-emitting device including anorganic compound on the release layer; and

an eleventh process for bonding a fifth substrate for sealing thelight-emitting device to the release layer with a second adhesive tosandwich the release layer between the fourth substrate and the fifthsubstrate.

Above-described structures relating to each method for manufacturing asemiconductor apparatus, wherein the solvent is water or alcohol.

Above-described structure relating to each method for manufacturing asemiconductor apparatus, wherein adhesiveness of the first two-sidedtape and the second substrate in the seventh process is stronger thanthat of the release layer and the fourth substrate.

It is preferable that a substrate that transfers to the release layerhave greater rigidity than that of a substrate that is transferred.

The above-described first and second structures relating to each methodfor manufacturing a semiconductor apparatus, wherein the first substrateis a glass substrate, the second and the third substrates are a quartzsubstrate or a metal substrate, and the fourth substrate and the fifthsubstrate are plastic substrates

The above-described first and second structures relating to each methodfor manufacturing a semiconductor apparatus, wherein a plastic substratehaving thermal conductivity can be bonded, the first substrate is aglass substrate, the second and the third substrates are a quartzsubstrate or a metal substrate, and among the fourth and the fifthsubstrate, one is a plastic substrate being transparent to light andanother is a plastic substrate having thermal conductivity.

Above-described structure relating to each method for manufacturing asemiconductor apparatus, wherein the fourth or the fifth substrate is aplastic substrate on the surface of which a SiN_(x) film, a SiN_(x)O_(y)film, an AlN_(x), film, or an AlN_(x)O_(y) film is formed. Thereliability of a semiconductor apparatus can be improved by forming aSiN_(x) film, a SiN_(x)O_(y) film, an AlN_(x) film, or an AlN_(x)O_(y)film over the plastic substrate to give a barrier property.

The process for bonding the second substrate with a two-sided tape andthe process of bonding the third substrate May be carried out whicheverfirst. Above-described structure relating to each method formanufacturing a semiconductor apparatus, wherein the order of a thirdprocess for bonding the second substrate to the organic resin film witha first two-sided tape to sandwich the release layer and the organicresin film between the first substrate and the second substrate, and afourth process for bonding a third substrate to the first substrate witha second two-sided tape can be reversed.

As used in this specification, the term “EL layer” refers to any layerprovided between a cathode and an anode. Therefore the above-describedhole injection layer, hole transporting layer, light-emitting layer,electron transporting layer, and electron injection layer may be all ELlayer.

As used in this specification, the term “EL device” refers to alight-emitting device having the structure that an EL material and alayer containing an organic material or inorganic material for injectingcarriers to the EL material (hereinafter, an EL layer) are interposedbetween two electrodes (an anode and a cathode) that is, a diodecomprising an anode, cathode, and an EL layer.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A to 1D are views according to Embodiment Mode 1;

FIGS. 2A and 2B are views according to Embodiment 2;

FIGS. 3A to 3J are views according to Embodiment Mode 2;

FIGS. 4A to 4J are views according to Embodiment Mode 3;

FIGS. 5A and 5B are views according to Embodiment 3;

FIG. 5 shows an electric characteristic of a TFT according to Embodiment1;

FIGS. 7A to 7F are views showing the connections of a TFT and a firstelectrode and a shape of a bank according to Embodiment 4;

FIGS. 8A to 8E are views of examples of electric appliances according toEmbodiment 5;

FIGS. 9A to 9C are views of examples of electric appliances according toEmbodiment 5;

FIGS. 10A and 10B are views showing a module according to Embodiment 6;

FIG. 11 is a block diagram according to Embodiment 6; and

FIGS. 12A and 12B are views showing a passive light-emitting apparatusaccording to Embodiment 7.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment Mode 1

An example of bonding an insulating substrate having high thermalconductivity or a substrate to a release layer (including a device) thatis separated by peeling-off method will be described in this embodimentmode.

In FIG. 1A, reference numeral 10 denotes an insulating substrate havingthermal conductivity; 11, an adhesive; and 12, a release layer(including a device). The release layer 12 includes a semiconductordevice formed on a substrate (not shown) in advance. The release layer12 is separated from a substrate by a peeled-off method and bonded tothe substrate 10 with the adhesive 11.

Specified quantity of powder such as Al, Mg, ceramics, or the like, andpowder of a low-melting metal (lead-free solders) are mixed intopolyphenylene sulfide or the like as thermoplastic resin, and themixture is pelletized. The resulted pellets may be formed into thesubstrate 10 having a curved surface by injection molding process orcompression molding process. The low-melting metal becomes melted due toheat by injection molding, and cooled, and then, hardened. In theresulted low-melting metal, fibrous metals are connected with each otherlike a network through scattered ceramics particles and formed a routefor thermal conduction. The resulted substrate 10 has such high thermalconductivity ranging from 5 to 30 W/mK. In addition, as a manufacturingmachine for melting and mixing resin composition, general mixing machinefor resin, rubber, or ceramics may be utilized. A mixing machine candisperse the powder of resin and low-melting metal each of which hasextremely different specified gravity. The melted and mixed resin andlow-melting metal in the mixing machine is extracted in the form oflump. The lump of composition is melted again and pelletized tofabricate particulate composition referred to as pellet. The pellet isformed into any shape by injection molding process.

A semiconductor apparatus can be completed by building a device (a TFT,a light-emitting device containing an organic compound, a liquid crystaldevice, a memory device, a thin film diode, a pin-junction siliconphotoelectric converter, a silicon resistance element, or the like)provided with the release layer 12 into the semiconductor apparatus. Thesemiconductor apparatus can radiate quickly heat generated in theapparatus by the substrate 10 during driving. Moreover, the heatradiation property can be improved by forming the thickness of theadhesive 11 into thin.

FIG. 1B is a view of an example of using an insulating substrate havingthermal conductivity that is molded into a flat sheet. Components inFIG. 1B except a substrate 20 are the same as of FIG. 1A and will not befurther explained. Through FIG. 1B, reference numeral 20 denotes aninsulating substrate having thermal conductivity; 11, an adhesive; and12, a release layer (including a device). The release layer 12 isseparated from a substrate (not shown) by a peeled-off method and bondedto the substrate 10 with the adhesive 11. The curved substrate 20 isillustrated in a cross-sectional view in FIG. 1B in order to show thatthe substrate 20 is flexible.

FIG. 1C is a view of an example of interposing a release layer between apair of substrates 20 and 24. In order that a release layer 22 isprotected against impurities dispersion from outside or physical forcefrom outside, the substrate 24 is bonded thereto with an adhesive 23 andsealed the release layer 22. The substrate 24 is a flexible plasticsubstrate or a thin curved glass substrate. In order to improve barrierproperty of the substrate, a single layer chosen from the groupconsisting of a SiN_(x) film, a SiN_(x)O_(y) film, an AlN_(x) film, oran AlN_(x)O_(y) film or a laminate layer of these films can be formed ona surface of the substrate 24.

Through FIG. 1C, reference numeral 20 denotes an insulating basematerial having thermal conductivity; 21, a first adhesive; 22, arelease layer (including a device); 23, a second adhesive; and 24, asubstrate. The release layer 22 is separated from a substrate (notshown) by a peeled-off method and bonded to the substrate 20 with thefirst adhesive 21. Or the substrate 24 is bonded to the release layer 22with the second adhesive 23, and the release layer is separatedtherefrom and bonded to the substrate 20 with the first adhesive 21.

FIG. 1D is a view of an example of interposing a release layer between apair of substrates 30 and 34 using a material having thermalconductivity as a adhesive 31.

Though FIG. 1D, reference numeral 30 denotes an insulating substratehaving thermal conductivity; 31, an adhesive having high thermalconductivity; 32, a release layer (including a device); 33, an adhesive;and 34, a substrate.

As the adhesive having high thermal conductivity 31, filler or powdercomposed of silver, nickel, aluminum, aluminum nitride, or the like(insulating thermal conductivity adhesive) may be used. The heatradiation property can be improved by using the adhesive having highthermal conductivity 31.

Embodiment Mode 2

An example of manufacturing an active matrix light emitting apparatuswill be described with reference to FIG. 3 in this embodiment mode 2.

The present invention can be applied to an active matrix light-emittingapparatus, but not exclusively, any light-emitting device as long asthat has a layer containing an organic compound such as a passive matrixlight-emitting apparatus for a color display panel, a surface luminous,or an area color light-emitting apparatus for electric spectacularsdevice.

First, a device is formed on a glass substrate (a first substrate 300).A metal film 301, which is a tungsten film (having a thickness rangingfrom 10 to 200 nm, preferably, from 50 to 75 nm) here, is formed on theglass substrate by sputtering, and an oxide film 302, which is a siliconoxide film (having a thickness ranging from 150 to 200 nm) here, isstacked thereon without exposing to the air. The tungsten film and thesilicon oxide films are formed over the edge portion of the substrate incase of using sputtering. It is preferable that the deposited tungstenfilm and silicon oxide film are removed selectively by O₂ ashing. In thefollowing peeling process, a boundary face of the tungsten film and asilicon oxide film or the internal silicon oxide film is separated.

Next, a silicon oxynitride film as a base insulating film (thickness of100 nm) is formed by PCVD, and an amorphous silicon film (thickness of54 nm) is stacked thereon without exposing the air.

The amorphous silicon film contains hydrogen. In the case of heating atnot less than 500° C. the amorphous silicon film to form a polysiliconfilm, hydrogen can be diffused as well as forming the polysilicon film.Various devices as typified by a TFT (a thin film diode, a pin-junctionsilicon photoelectric converter, a silicon resistance element, a sensordevice (typically, a pressure-sensitive fingerprints sensor usingpolysilicon)) can be formed by using the resulted polysilicon film. Inaddition, the present invention can be applied to the TFT that uses anamorphous silicon film as an active layer.

Here, a polysilicon film is formed by using known technique (solid-phasegrowth, laser crystallization, crystallization using catalyst metal),and an island like semiconductor region is formed by patterning, then, atop gate TFT 303 is formed that uses the island like semiconductorregion as an active layer. A gate insulating film is formed, a gateelectrode is formed, and a source or a drain region is formed by dopingto the active layer, then, an interlayer insulating film is formed, andthen, a source or a drain electrode is formed, respectively. Lastly, anactivation is carried out.

Next, a film containing an organic compound (hereinafter, organiccompound layer) is interposed between a pair of electrodes (an anode anda cathode). Then, a first electrode for forming a light-emitting devicethat can achieve fluorescence or phosphorescence by applying electronicfield to the pair of electrodes is formed. Here, the first electrode 304that can serve as an anode or a cathode is formed of a large workfunction metal film (Cr, Pt, W, or the like), or a transparentconductive film (Indium tin oxide alloy (ITO), indium oxide zinc oxidealloy (In₂O₃—ZnO), zinc oxide (ZnO), or the like). An example of formingthe first electrode 304 for serving as an anode is described.

In case that the source electrode or the drain electrode of a TFT servesas a first electrode, or a first electrode in contact with the sourceregion or a drain region is formed separately, the TFT includes thefirst electrode.

A bank 305 a is formed on the edge portion of the first electrode(anode) as encircling the periphery of the first electrode. To improvecoverage, the upper edge portion or the bottom edge portion of the bankis formed to have a curved surface having curvature. For example, in thecase that a positive type photosensitive acrylic is used as a materialfor the bank, it is preferable that only the upper edge portion of thebank is formed to have a curved surface having radius of curvature (from0.2 to 3 μm). Either a negative type that is an insoluble material inetchant according to light to which photosensitive material is exposedor a positive type that is dissoluble in etchant according to light canbe used as the bank.

Further, in the case of stacking a plurality of organic resin, there isa threat that a part the plural organic resin is melted or the pluralorganic resin is too adhesive. Therefore, in the case of using organicresin as a material for the bank, the bank 305 a is preferable to becovered by an inorganic insulating film (a SiN_(x) film, a SiN_(x)O_(y)film, an AlN_(x) film, or an AlN_(x)O_(y) film) in order make it easy toremove water-soluble resin after coating it over the whole surface inthe following process. The inorganic insulating film serves as a part ofthe bank 305 b (FIG. 3A).

Next, an adhesive that is soluble in water or alcohol is coated over thewhole surface and baked. The adhesive may be composed of, for example,epoxy series, acrylate series, silicon series, or the like. Here, a filmformed of water-soluble resin (TOAGOSEI Co., Ltd.: VL-WSHL10) 306 isspin-coated to have a thickness of 30 μm, and exposed for two minutes tobe partially cured, then, exposed its back to UV rays for 2.5 minutes,and then, exposed its surface for 10 minutes to be fully cured (FIG.3B).

The adhesiveness of the metal film 301 and, the oxide film 302 is partlyweakened for easy peeling-off. The partly wakening process ofadhesiveness is carried out by irradiating laser light on the regionthat is to be peeled-off of the metal film 301 or the oxide film 302along with the periphery thereof, or pressuring locally from outside onthe region that is to be peeled-off along with the periphery thereof fordamaging the inside or a part of the boundary face of the oxide film302. Specifically, a hard needle such as a diamond pen may be attachedperpendicular to the region to be peeled-off and moved along with theperiphery thereof with applying loading. Preferably, a scriber devicecan be used to move with applying loading on the region with press forceranging from 0.1 to 2 mm. It is important to carry out some processesfor easy peeling-off, that is, prepare for peeling-off process. Suchpreparatory process for weakening selectively (partly) the adhesivenesswill prevent poor peeling-off and improve process yield.

Next, a second substrate 308 is bonded to a film formed of water-solubleresin 306 with a two-sided tape 307. Then, a third substrate 310 isbonded to the first substrate 300 with a two-sided tape 309 (FIG. 3C).The third substrate 310 prevents the first substrate 300 from damagingin the following peeling-off process. For the second substrate 308 andthe third substrate 310, the substrate that has higher rigidity thanthat of the first substrate 300, for example, a quartz substrate or asemiconductor substrate, is preferably to be used.

The first substrate 300 provided with the metal film 301 is peeled-offfrom the region, which is partly weakened its adhesiveness by a physicalmeans. The first substrate 300 can be peeled-off by comparatively smallforce (for example, man's hand, air pressure of gas sprayed from anozzle, ultrasonic waves, or the like). Thus, the release layer formedon the oxide layer 302 can be separated from the first electrode 300.FIG. 3D is a state of after peeling-off process.

Next, a fourth substrate 312 is bonded to the oxide layer 302 (and thepeeling-off layer) with the adhesive 311 (FIG. 3E). It is important thatthe adhesive strength of the fourth substrate 312 and the oxide layer302 (and the release layer) is higher than that of the second substrate308 and the release layer by the two-sided tape 307.

It is preferable that a plastic substrate having high thermalconductivity ranging from 2 to 30 W/mK is used for the fourth substrate312. The plastic substrate is formed of a mixture of ceramics; lead-freesolders; and synthetic resin composed of polypropylene, polypropylenesulfide, polycarbonate, polyetherimide, polyphenylene sulfide,polyphenylene oxide, polysulfone, or polyphthalamide. In the plasticsubstrate, melted metals are connected each other like a network throughceramics particles.

As the adhesive 311, various types of curing adhesive, for example, aphoto-curing adhesive such as a reaction-curing adhesive, a heat-curingadhesive, a UV-curing adhesive, or the like, or an anaerobiotic adhesiveis utilized. It is more preferable that the adhesive 311 be containingpowder composed of silver, nickel, aluminum, aluminum nitride, or fillerto have high thermal conductivity.

The second substrate 308 is removed from the two-sided tape 307 (FIG.3F).

Then, the two-sided tape 307 is removed from the film formed ofwater-soluble resin 306 (FIG. 3G).

And then, the film formed of water-soluble resin 305 is melted withwater and removed (FIG. 3H). If residue of the water-soluble resin isleft on the first electrode 304, it will cause the deterioration of thedevice. Consequently, it is preferable that the surface of the firstelectrode 304 be rinsed or treated in O₂ plasma.

If it is necessary, the surface of the first electrode 304 is rubbed andwashed by using a porous sponge (typically, a sponge of PVA (polyvinylalcohol) or nylon) soaked in a surfactant (weak alkaline).

Immediately prior to forming a layer containing an organic compound 313,the substrate is heated in a vacuum for removing absorbed moisture inthe whole substrate that is provided with a TFT and a bank. Moreover,the first electrode may be exposed to ultraviolet radiation immediatelyprior to forming the layer containing the organic compound 313.

The layer containing the organic compound 313 is formed selectively overthe first electrode (anode) by vapor deposition using an evaporationmask or ink-jetting. As the layer containing the organic compound 313, apolymer material, a low molecular material, an inorganic material, amixed layer formed of the above materials, a layer formed by dispersingabove materials, or a lamination layer formed by stacking appropriatecombination of the above materials.

A second electrode (cathode) 314 is formed on the layer containing theorganic compound 303 (FIG. 3I). For forming the cathode 314, alamination layer of a thin film, which has a thickness of beingtransparent to light, formed of a small work function material (Al, Ag,Li, Ca, or alloy of these materials such as MgAg, MgIn, AlLi, CaF₂, orCaN) and a transparent conductive film is utilized. If necessary, aprotective layer is formed for covering the second electrode bysputtering or vapor deposition. The transparent protective laminationlayer may be formed of a silicon nitride film, silicon oxide film, asilicon nitride oxide film (SiNO film: a ratio of N to O composition isN>O)), or silicon oxynitride (SiON film: a ratio of N to O compositionis N<O), or a thin film containing carbon as its main component (forexample, DLC film, or CN film) formed by sputtering or CVD.

A sealing agent (not shown) containing a gap agent for keeping a spacebetween a pair of substrate is applied in a desired pattern to a fifthsubstrate 316 that serves as a sealing substrate. The fifth substratemay be transparent to light in the present case since an example of thelight-emitting device in which light generated therein emit through thefifth substrate 316 is described. In order to lighten the device, aplastic film on which a barrier film (a SiN_(x) film, a SiN_(x)O_(y)film, an AlN_(x) film, or an AlN_(x)O_(y) film) is formed is used forthe fifth substrate 316. Then, the sealing substrate (the fifthsubstrate) applied with a sealing agent is bonded to an active matrixsubstrate so that the sealing pattern is aligned to encircle thelight-emitting portion for sealing the light-emitting device. Inaddition, the sealing substrate is bonded so that the space encircled bythe sealing agent is filled with an adhesive 315 formed of a transparentorganic resin (FIG. 3J).

In consequence, a light-emitting apparatus provided with a TFT and alight-emitting device including the plastic substrate 312 having highthermal conductivity and the fifth substrate 316 as a support medium.The resulted light-emitting apparatus can radiate heat generated in thedevice during driving operation since the plastic substrate has highthermal conductivity. Further, the light-emitting apparatus can bemanufactured into be thin, light-weight, and flexible since plasticsubstrate is used as a support medium.

Here, a peeling-off process that separates the first substrate bysplitting the region of the boundary face of a tungsten film and asilicon oxide film is used, but not exclusively, the first substrate maybe separated by laser irradiation after forming an amorphous siliconfilm containing hydrogen on the first substrate, or by etching ormechanical etching using solution or gas.

This embodiment mode can be freely combined with Embodiment Mode 1.

Embodiment Mode 3

An example of a method for manufacturing a light-emitting apparatus inwhich light generated in a light-emitting device is extracted through afirst electrode will be described. Since partway of this embodiment modeis the same as Embodiment Mode 2, further explanation will be omitted,and like components are denoted by like numerals as of Embodiment Mode2.

The process up to peeling-off the first substrate is the same asEmbodiment Mode 2. Note that a transparent conductive film is used for afirst electrode 304 in order to transmit light.

When the state shown in FIG. 4D is achieved according to Embodiment Mode2, a transparent plastic substrate 412 is bonded thereto with anadhesive 411 (FIG. 4E).

A second substrate 308 is separated from the two-sided tape 307 (FIG.4F).

Then, the two-sided tape 307 is removed (FIG. 4G).

And then, the film formed of water-soluble resin 306 is melted by waterand removed (FIG. 4H). If residue of the water-soluble resin is left onthe first electrode 304, it will cause the deterioration of the device.Consequently, it is preferable that the surface of the first electrode304 is rinsed or treated in O₂ plasma.

If it is necessary, the surface of the first electrode 304 is rubbed andwashed by using a porous sponge (typically, a sponge of PVA (polyvinylalcohol) or nylon) soaked in a surfactant (weak alkaline).

Immediately prior to forming a layer containing an organic compound 413,the substrate is heated in a vacuum for removing adsorbed moisture inthe whole substrate that is provided with a TFT and a bank. Moreover,immediately prior to forming the layer containing the organic compound413, the first electrode may be exposed to ultraviolet radiation.

The layer containing the organic compound 413 is formed selectively overthe first electrode (anode) by vapor deposition using an evaporationmask or ink-jetting. As the layer containing the organic compound 413, apolymer material, a low molecular material, an inorganic material, amixed layer formed of the above materials, a layer formed by dispersingabove materials, or a lamination layer formed by stacking appropriatecombination of the above materials.

A second electrode (cathode) 414 is formed on the layer containing theorganic compound 413 (FIG. 4I). For forming the cathode 414, alamination layer of a thin film, which is transparent to light, formedof a small work function material (Al, Ag, Li, Ca, or alloy of thesematerials such as MgAg, MgIn, AlLi, CaF₂, or CaN) is utilized. Ifnecessary, a protective layer is formed for covering the secondelectrode by sputtering or vapor deposition. The protective laminationlayer may be formed of a silicon nitride film, silicon oxide film, asilicon nitride oxide film (SiNO film: a ratio of N to O composition isN>O)), or silicon oxynitride (SiON film: a ratio of N to O compositionis N<O), or a thin film containing carbon as its main component (forexample, DLC film, or CN film) formed by sputtering or CVD.

A sealing agent (not shown) containing a gap agent for keeping a spacebetween a pair of substrate is applied in a desired pattern to a fifthsubstrate 416 that serves as a sealing substrate. The fifth substrate416 can be translucent or opaque in the present case since an example ofthe light-emitting device in which light generated therein emit throughthe third substrate 412 is described. Then, the fifth substrate 416applied with a sealing agent is bonded to an active matrix substrate sothat the sealing pattern is aligned to encircle the light-emittingportion for sealing the light-emitting device. In addition, the sealingsubstrate is bonded so that the space encircled by sealing agent isfilled with an adhesive 415 formed of a transparent organic resin (FIG.4J).

In consequence, a light-emitting apparatus provided with a TFT and alight-emitting device including the plastic substrate 412 having highthermal conductivity and the fifth substrate 416 as a support medium.The resulted light-emitting apparatus can radiate heat generated in thedevice during driving operation since the plastic substrate has highthermal conductivity. Further, the light-emitting apparatus can bemanufactured to be thin, light-weight, and flexible since plasticsubstrate is used as a support medium.

This embodiment mode can be freely combined with Embodiment Mode 1 orEmbodiment Mode 2.

The present invention having above-described constitution will befurther explained with the following embodiments.

Embodiment 1

Here, a method of simultaneously manufacturing TFTs (an n-channel TFTand a p-channel TFT) on a substrate will be described in detail.Although shown here is an example of an active matrix substratefabricating process up to and including a TFT fabricating process, thereis no limitation. It is needless to say that a light-emitting apparatushaving a light-emitting layer containing an organic compound can bemanufactured, if the arrangement of TFTs and the materials of pixelelectrodes are appropriately changed.

A glass substrate (#1737) is used as a substrate. First, a siliconoxynitride layer is formed to have a thickness of 100 nm on thesubstrate by PCVD.

Subsequently, a tungsten layer is formed to have a thickness of 50 nm bysputtering as a metal layer, and a silicon oxide layer is continuouslyformed to have a thickness of 200 nm by sputtering as an oxide layerwithout being exposed to the atmosphere. The silicon oxide layer isformed under the conditions, that is, a RF sputtering apparatus is used;a silicon oxide is used as sputtering targets (the diameter of 30.5 cm);argon gas for heating the substrate is 30 sccm; the substratetemperature is 300° C.; the pressure is 0.4 Pa; the electric power is 3kW; and argon flow rate/oxygen flow rate=10 sccm/30 sccm.

Subsequently, the tungsten layer formed on the periphery portions or theedges of the substrate is removed by O₂ ashing.

Subsequently, a silicon oxynitride film is formed using SiH₄ and N₂O asmaterial gases (composition ratio: Si=32%, O=59%, N=7%, H=2%) into alamination layer to have a thickness of 100 nm at 300° C. by PCVD.Further, a semiconductor film having an amorphous configuration (in thiscase, amorphous silicon film) is formed to have a thickness of 54 nmwith SiH₄ gas at 300° C. by PCVD without exposure to an atmosphere. Thisamorphous silicon film contains hydrogen, the hydrogen will be diffusedby a subsequent heat treatment, and the amorphous silicon film can bepeeled-off by a physical means in the inside of the oxide layer or theinterface of the oxide layer.

Then, a nickel acetate salt solution containing nickel of 10 ppm byweight is coated by a spinner. Nickel elements can be sputtered on theentire surface instead of being coated. Then, heat treatment is carriedout to crystallize and form a semiconductor film having a crystallineconfiguration (here, a polysilicon layer). Here, after the heattreatment (500° C. for 1 hour) for dehydrogenation is carried out, andthe heat treatment (550° C. for 4 hours) for crystallization is carriedout, then, a silicon film having a crystalline configuration is formed.Also, the heat treatment (5.00° C. for 1 hour) for dehydrogenation hasalso a function of a heat treatment for diffusing the hydrogen containedin the amorphous silicon layer to a boundary face between a W film and asilicon oxide layer. Also note that, although a crystallizationtechnique using nickel as a metal element for promoting crystallizationof silicon is used here, other known crystallization technique, forexample, a solid-phase growth method and a laser crystallization methodmay be used.

Next, after the oxide film on the surface of the silicon film having acrystalline configuration is removed by dilute hydrofluoric acid or thelike, laser light (XeCl: wavelength of 308 nm) is irradiated thereon forraising a crystallization rate and repairing defects remaining incrystal grains is performed in an atmosphere or in an oxygen atmosphere.Excimer laser light with a wavelength of 400 nm or less, o secondharmonic wave or third harmonic wave of a YAG laser is used for thelaser light. In any case, pulse laser light with a repetition frequencyranging approximately from 10 to 1000 Hz is used, the pulse laser lightis condensed to 100 to 500 mJ/cm² by an optical system, and irradiatedwith an overlap ratio of 90 to 95%, whereby the silicon film surface maybe scanned. Here, laser light is irradiated in an atmosphere in thecondition of a repetition frequency of 30 Hz and energy density of 470mJ/cm². Note that an oxide film is formed on the surface by the firstlaser light irradiation since the irradiation is conducted in anatmosphere or in an oxygen atmosphere. Though an example of using thepulse laser is shown here, the continuous oscillation laser may also beused. When an amorphous semiconductor film is crystallized, it ispreferable that the second harmonic through the fourth harmonic of basicwaves is applied by using the solid state laser which is capable ofcontinuous oscillation in order to obtain a crystal in a large grainsize. Typically, it is preferable that the second harmonic (having awavelength of 532 nm) or the third harmonic (having a wavelength of 355nm) of an Nd: YVO₄ laser (basic wave of 1064 nm) is applied.Specifically, laser beams emitted from the continuous oscillation typeYVO₄ laser with 10 W output is converted into a harmonic by using thenon-linear optical elements. Also, a method of emitting a harmonic byapplying YVO₄ crystal and the non-linear optical elements into aresonator can be given. Then, more preferably, the laser beams areformed so as to have a rectangular shape or an elliptical shape by anoptical system, and irradiated on the surface. At this time, the energydensity of approximately 0.01 to 100 MW/cm² (preferably 0.1 to 10MW/cm²) is required. The semiconductor film is irradiated with the laserlight by moving relatively at approximately 10 to 2000 cm/s ratecorresponding to the laser beams.

In addition to the oxide film formed by this laser irradiation, abarrier layer comprising an oxide film is formed to have a thicknessranging from 1 to 5 nm in total by treating the surface with ozone waterfor 120 seconds. Though the barrier layer is formed by using ozone waterhere, ultraviolet light may be irradiated in an oxygen atmosphere to thesurface of the semiconductor film having the crystal structure in orderto be oxidized or the surface of the semiconductor film having thecrystal structure may be treated in oxide plasma in order to be oxidizedfor forming the barrier layer. In addition, a barrier layer may beformed by forming an oxide film having a thickness approximately rangingfrom 1 to 10 nm by PCVD, sputtering, vapor deposition, or the like.Further, the oxide film formed by the laser light irradiation may beremoved before forming the barrier layer.

On the barrier layer, an amorphous silicon film containing argonelements, which serve as a gettering site, is formed to have a thicknessranging from 10 to 400 nm, in this embodiment, 100 nm by sputtering. Inthis embodiment, an amorphous silicon film containing argon is formedunder an atmosphere containing argon using silicon targets. Theamorphous silicon film containing argon is formed in the depositionconditions, that is, a flow ratio of monosilane to argon (SiH₄:Ar) is1:99; pressure is 6.565 Pa (0.05 Torr); RF power density is 0.087 W/cm²;and temperature is 350° C. in the case of using PCVD.

Then, an oven heated at 550° C. is used for heat treatment for 3 minutesfor gettering to reduce the nickel concentration in the semiconductorfilm having a crystal structure. A lamp annealing apparatus may be usedinstead of the oven.

Subsequently, the amorphous silicon film containing the argon element,which serves the gettering site, is selectively removed using thebarrier layer as an etching stopper, thereafter the barrier layer isselectively removed by dilute hydrofluoric acid. Note that since nickelis likely to move to a region having a high oxygen concentration duringgettering, it is desirable that the barrier layer comprised of the oxidefilm is removed after the gettering.

Then, after a thin oxide film is formed from ozone water on the surfaceof the obtained silicon film having a crystal structure (also referredto as polysilicon film), a mask made of resist is formed, and an etchingprocess is conducted thereto to obtain a desired shape, thereby formingthe island-like semiconductor layers separated from one another. Afterthe formation of the semiconductor layers, the mask made of resist isremoved.

Through the above processes, a nitride layer (a metal layer), an oxidelayer, and a base insulating film are formed on a substrate to obtain asemiconductor film having a crystal structure. And, the semiconductorfilm is etched into isolated island like semiconductor films havingdesired shapes. Then, a TFT that uses the resulted semiconductor layersas an active layer is fabricated.

Next, the oxide film is removed with the etchant containing hydrofluoricacid, and at the same time, the surface of the silicon film is washed.Thereafter, an insulating film containing silicon as its maincomponents, which serves as a gate insulating film, is formed. In thisembodiment, a silicon oxynitride film (composition ratio: Si=32%, O=59%,N=7%, H=2%) is formed to have a thickness of 115 nm by PCVD.

Next, a first conductive film having a thickness ranging from 20 to 100nm and a second conductive film having a thickness ranging form 100 to400 nm are stacked on the gate insulating film. In this embodiment, a 50nm-thick tantalum nitride film and a 370 nm-thick tungsten film aresequentially stacked on the gate insulating film.

As a conductive material for forming the first conductive film and thesecond conductive film, an element selected from the group consisting ofTa, W, Ti, Mo, Al and Cu, or an alloy material or a compound materialcontaining the above elements as its main Components is utilized.Further, a semiconductor film as typified by a polycrystalline siliconfilm doped with an impurity element such as phosphorous or an AgPdCualloy may be used as the first conductive film and the second conductivefilm. In addition, the present invention is not limited to a two-layerstructure. For example, a three-layer structure may be adopted in whicha 50 nm-thick tungsten film, an alloy film of aluminum and silicon(Al—Si) of 50.0 nm-thick, and a 30 nm-thick titanium nitride film aresequentially stacked. Moreover, in case of a three-layer structure,tungsten nitride may be used instead of tungsten of the first conductivefilm, an alloy film of aluminum and titanium (Al—Ti) may be used insteadof the alloy film of aluminum and silicon (Al—Si) of the secondconductive film, and a titanium film may be used instead of the titaniumnitride film of the third conductive film. In addition, a single layerstructure may also be adopted.

Next, resist masks are formed by light exposure. Then, a first etchingtreatment is carried out for forming gate electrodes and wirings. Thefirst etching treatment is carried out under the first and the secondetching conditions. It is preferable to carry out ICP (inductivelycoupled plasma) etching. The films can be etched to have desired tapershapes by ICP etching in suitably adjusted etching conditions (that is,the amount of power applied to a coiled electrode, the amount of powerapplied to an electrode on the substrate side, the temperature of theelectrode on the substrate side, etc.). As etching gas, chlorine-basedgas as typified by Cl₂, BCl₃, SiCl₄, or CCl₄, fluorine-based gas astypified by CF₄, SF₆, or NF₃, or O₂ are appropriately utilized.

Through the above described first etching process, each the edge portionof the first conductive layer and the second conductive layer is fortedto have a tapered shape due to the effect of the bias voltage applied tothe substrate side by forming the shape of the resist mask into anappropriate shape. The angle of the tapered portion may be ranging from15 to 45°.

Thus, first shape conductive layers that comprise the first conductivelayer and the second conductive layer are formed by the first etchingprocess. Ranging appropriately from 10 to 20 nm-thick insulating film,which serves as the gate insulating film, is etched. Consequently, theregion that has thin thickness and is not covered by the first shapeconductive layers becomes a gate insulating film.

Next, a second etching process is conducted without removing the masksformed of resist.

By the second etching process, the taper angle of W becomes 70′. Thesecond conductive layer is formed by the second etching process. On theother hand, the first conductive layers are hardly etched. Practically,the width of the first conductive layer may be reduced approximately 0.3μm, namely, approximately 0.6 μm the total line width in comparison withbefore carrying out the second etching process. Thus, the size of thetaper of the first conductive layer is hardly changed.

Next, the resist masks are removed, and a first doping process iscarried out. Ion doping or ion implantation may be carried out as thedoping process. Ion doping is carried out under the conditions of adosage of 1.5×10¹⁴ atoms/cm² and an accelerating voltage ranging from 60to 100 keV. As an impurity element imparting n-type conductivity,phosphorous (P) or arsenic (As) is typically used. In this case, thefirst conductive layer and the second conductive layer become masksagainst the impurity element imparting n-type conductivity, and firstimpurity regions are formed in a self-aligning manner. The impurityelement imparting n-type conductivity is added to the first impurityregions in a concentration range of 1×10¹⁶ to 1×10¹⁷/cm³. Here theregion having the same concentration range as the first impurity regionis also referred to as an n⁻⁻ region.

Note that although the first doping process is carried out afterremoving the resist masks in this embodiment, the first doping processmay be carried out without removing the resist masks.

Next, resist masks are formed (a mask for protecting a channel formationregion of a semiconductor layer to which a p-channel TFT of a drivercircuit is formed and the periphery thereof, mask for protecting achannel formation region of a semiconductor layer to which one ofn-channel TFTs is formed and the periphery thereof a mask for protectinga channel formation region of a semiconductor layer to which a TFT of apixel portion is formed, the periphery thereof, and a retention volumeregion), and a second doping process is carried out. The ion doping ofphosphorous (P) is carried out in the second doping process under theconditions, that is, a dosage is 1.5×10¹⁵ atoms/cm²; and an acceleratingvoltage is ranging from 60 to 100 keV. Here, impurity regions are formedin the respective semiconductor layers in a self-aligning manner usingthe second conductive layers as masks. Of course, phosphorous is notadded to the regions covered by the masks. Thus, second impurity regions140 to 142 and a third impurity region 144 are formed. Impurity elementsimparting n-type conductivity are added to the second impurity regionswith concentrations ranging form 1×10²⁰ to 1×10²¹/cm³. Here, the regionhaving the same concentrations as the second impurity region is alsoreferred to as an n⁺ region.

Further, the third impurity region is formed at a lower concentrationthan the second impurity region using the first conductive layer, and isdoped with impurity elements imparting n-type conductivity withconcentrations ranging from 1×10¹⁸ to 1×10¹⁹/cm³. Note that sinceimpurity elements are doped to the third impurity region passing throughthe first conductive layer in a tapered shape, the concentrationgradient in the third impurity region can be seen as impurityconcentrations are increased toward the edge portion of the taperedportion. Here, the region having the same concentrations as the thirdimpurity region is referred to as an n⁻ region.

Next, after the masks formed of resist are removed, new masks formed ofresist are formed (masks for covering the n-channel TFT). Then, a thirddoping process is carried out.

In the driving circuit, by the third doping process as described above,fourth impurity regions and fifth impurity regions are formed in whichimpurity elements imparting p-type conductivity are doped to thesemiconductor layer that is for forming the p-channel TFT and to thesemiconductor layer that is for forming a retention volume.

Further, impurity elements imparting p-type conductivity withconcentrations ranging from 1×10²⁰ to 1×10²¹/cm³ is doped to the fourthimpurity regions. Note that, although phosphorous (P) has been doped tothe fourth impurity regions (n⁻⁻ region) in the preceding step, impurityelements imparting p-type conductivity with concentrations of 1.5 to 3times higher than that of phosphorous, so that the fourth impurityregion is p-type. Here, the region having the same concentrations as thefourth impurity region is also referred to a p⁺ region.

Further, fifth impurity regions are formed in regions overlapping thetapered portion of the second conductive layer, and are added withimpurity elements imparting p-type conductivity with concentrationsranging from 1×10¹³ to 1×10²⁰/cm³. Here, the region having the sameconcentrations as the fifth impurity region is also referred to as a p⁻region.

Through the above-described processes, the impurity regions havingn-type or p-type conductivity are formed in the respective semiconductorlayers.

Next, an insulating film that covers substantially the entire surface isformed. In this embodiment, a 50 nm-thick silicon oxide film is formedby PCVD. Of course, the insulating film is not limited to a siliconoxide film, but another insulating films containing silicon of a singlelayer or a lamination layer.

Then, a process of activating impurity elements doped to the respectivesemiconductor layers is carried out. This activation process is carriedout by a rapid thermal annealing (RTA) using a lamp light source, a YAGlaser or an excimer laser irradiation onto the back surface, heattreatment using a furnace, or a combination thereof.

Further, although an example of forming the insulating film before theactivation is shown in this embodiment, the insulating film may beformed after the activation.

Next, a first interlayer insulating film formed of a silicon nitridefilm is formed, and heated (300 to 550° C. for 1 to 12 hours). Then, thesemiconductor layer is hydrogenated for terminating dangling bonds ofthe semiconductor layers using hydrogen in the first interlayerinsulating film. The semiconductor layers can be hydrogenatedirrespective of the existence of an insulating film formed of a siliconoxide film. Incidentally, in this embodiment, a material containingaluminum as its main components is used for the second conductive layer,and thus, it is important that the hydrogenation is carried out undersuch the heat treatment condition that the second conductive layer canwithstand. In addition, a plasma hydrogenation (using hydrogen excitedby plasma) may be also carried out.

Next, a second interlayer insulating film is formed using an organicinsulating material on the first interlayer insulating film. In thisembodiment, an acrylic resin film is formed to have a thickness of 1.6μm. A third interlayer insulating film is formed using a silicon nitridefilm. Then, a contact hole that reaches a source wiring and contactholes that reach the respective impurity regions are formed.

Thereafter, a source electrode or a drain electrode is formed using Al,Ti, Mo, W, or the like.

As described above, an n-channel TFT and a p-channel TFT can be formed.

Lastly, a plastic substrate is pasted, and the layer including TFTs areseparated from the substrate. In the case of using high conductivitymaterials for the plastic substrate, high reliable semiconductorapparatus that has high heat radiating property can be manufactured.

A plastic substrate is formed using the resin that is made in the wayhereinafter described that ceramics and low-melting point metals(lead-free solders such as tin, bismuth, and zinc) are mixed insynthetic-resin composed of polypropylene, polypropylene sulfide,polycarbonate, polyetherimide, polyphenylene sulfide, polyphenyleneoxide, polysulfone, or polyphthalamide to have high thermal conductivityranging from 2 to 30 W/mK.

The substrate can be peeled-off if the mechanical strength of the layerincluding a TFT (a release layer) is sufficiently that is formed on theoxide layer.

The TFT characteristics are not changed by the peeling-off. FIG. 6 showselectric characteristics of a p-channel type TFT.

In this embodiment, an example of peeling-off the substrate at the stateof forming the TFT and transferring to the plastic substrate, however,the substrate can also be peeled-off after forming a light-emittingdevice using a layer including a bank, a layer containing an organiccompound, or the like, and transferred to the plastic substrate.Further, an opposing substrate may be bonded by using the electrode ofthe TFT as a reflection electrode, and liquid crystals are filled intherebetween, then, the substrate may be peeled-off, the release layeris bonded to the plastic substrate for manufacturing a reflective liquidcrystal display apparatus.

This embodiment can be freely combined with any one of Embodiment Mode 1to Embodiment Mode 3.

Embodiment 2

In this embodiment, an example of manufacturing a light-emittingapparatus (top emission structure) provided with a light-emitting deviceincluding an organic compound layer as a light-emitting layer on asubstrate having an insulating surface is described with reference toFIG. 2.

FIG. 2A is a top-surface view of a light-emitting apparatus. FIG. 2B isa cross-sectional view of FIG. 2A taken along the line of A-A′.Reference numeral 1101 denoted by a dotted line denotes a source signalline driver circuit; 1102 denotes a pixel portion; 1103, a gate signalline driver circuit; 1104, a transparent sealing substrate; and 1105, afirst sealing agent. Space encircled by the first sealing agent 1105 isfilled with a transparent second sealing agent 1107. In addition, thefirst sealing agent 1105 contains a gap agent for keeping the intervalof substrates.

Further, reference numeral 1108 denotes a wiring for transmittingsignals inputted to the source signal line driver circuit 1101 and thegate signal line driver circuit 1103. The wiring 1108 receives a videosignal or clock signal from a FPC (flexible printed circuit) 1109 thatserves as an external input terminal. Although only FPC is illustrated,a printed wiring board (PWB) may be attached to the FPC.

The cross-sectional structure of the light-emitting apparatus isdescribed with reference FIG. 2B. A driver circuit and a pixel portionare formed on a substrate having high thermal conductivity 1110 via anadhesive 1140. In FIG. 2B, the source signal line driver circuit 1101 isillustrated as a driver circuit and the pixel portion 1102 isillustrated. Heat generated in the driver circuit and the pixel portioncan be radiated by the substrate having high thermal conductivity 1110.A plastic substrate is formed using the resin that is made in the wayhereinafter described, that is, ceramics such as boron nitride, aluminumnitride, magnesium oxide, beryllium nitride, or the like, and lead-freesolders are mixed in synthetic-resin composed of polypropylene,polypropylene sulfide, polycarbonate, polyetherimide, polyphenylenesulfide, polyphenylene oxide, polysulfone, or polyphthalamide to havehigh thermal conductivity ranging from 2 to 30 W/mK. This embodimentcorresponds to the structure shown in FIG. 1C described in EmbodimentMode 1.

A CMOS circuit comprising an n-channel TFT 1123 and a p-channel TFT 1124is formed as the source signal driver circuit 1101. These TFT may alsobe obtained according to Embodiment 1. A TFT for forming the drivecircuit can be formed by known CMOS circuit, PMOS circuit, or NMOScircuit. In this embodiment, a driver integrated circuit in which adriver circuit is formed on the substrate is shown, however, but notexclusively, the driver circuit can be formed outside instead of overthe substrate. The structure of the TFT is not exclusive, either a topgate TFT or a bottom gate TFT may be utilized.

The pixel portion 1102 is formed from a plurality of pixels each ofwhich includes a switching TFT 1111, a current controlling TFT 1112, anda first electrode (anode) 1113 which is electrically connected to adrain of the current-controlling TFT 1112. The current controlling TFT1112 may be either an n-channel type TFT or a p-channel type TFT, butwhen it is connected to the anode, it is preferable to be a p-channeltype TFT. It is also preferable that a storage capacitor (not shown) beappropriately provided. Here, though the cross-sectional structure ofonly one pixel out of thousands of pixels having two TFTs isexemplified, three more TFTs can be provided appropriately with the onepixel.

Since the first electrode 1113 is directly connected to the drain of theTFT, it is preferable that a lower layer of the first electrode 1113 beformed of the material that can be an ohmic contact with the draincontaining silicon and an uppermost layer of the first electrode 1113which is in contact with an organic compound layer be formed of thematerial that has a large work function. For example, a three-layerstructure comprising a titanium nitride film, a film containing aluminumas its main components, and a titanium nitride film, can have a lowresistance as a wiring, and be a favorable ohmic contact with the drain,and also, serve as an anode. Further, the first electrode 1113 may beformed of a single layer such as a titanium nitride film, a chromiumfilm, a tungsten film, a zinc film, a platinum film or the like, or alamination layer of three or more layers.

Insulator 1114 (referred to as a bank, or the like) are formed to coverthe edge of the first electrode (anode) 1113. The insulator 1114 may beformed of either an organic resin film or an insulating film containingsilicon. Here, the insulator 1114 is formed into the shape as shown inFIG. 2 using a positive type photosensitive acrylic resin film

To improve coverage, the upper edge portion or the bottom edge portionof the insulator 1114 is formed to have a curved surface havingcurvature. For example, in the case that a positive type photosensitiveacrylic is used as a material for the insulator 1114, it is preferableto form only the upper edge portion of the insulator 1114 b having acurved surface having radius of curvature (ranging from 0.2 to 3 μm).Either a negative type that become an insoluble material in etchantaccording to light for photosensitive material or a positive type thatbecome dissoluble in etchant according to light for photosensitivematerial can be used as an insulator 1114.

In addition, the insulator 1114 may be covered by a protective filmformed of an aluminum nitride film, an aluminum nitride oxide film, athin film containing carbon as its main components, or a silicon nitridefilm.

An organic compound layer 1115 is selectively formed over the firstelectrode (anode) 1113 by vapor deposition using an evaporation mask orink-jetting. Further, a second electrode (cathode) 1116 is formed overthe organic compound layer 1115. As the cathode, a material having asmall work function (for example, Al, Ag, Li, Ca, or alloys thereof suchas MgAg, MgIn, AlLi, CaF₂, or CaN) may be used. In this embodiment, thesecond electrode (cathode) 1116 is formed of a lamination layer of ametal thin film having a thin thickness and a transparent conductivefilm (for example, an indium oxide-tin oxide alloy (ITO), an indiumoxide-zinc oxide alloy (In₂O₃—ZnO), zinc oxide (ZnO), or the like) inorder that the second electrode may transmit luminescence. Alight-emitting device 1118 comprising the first electrode (anode) 1113,the organic compound layer 1115, and the second electrode (cathode) 1116is thus fabricated. In this embodiment, since the example of thelight-emitting device 1118 that emits white light is exemplified, acolor filter (for ease of explanation, an overcoat layer is not shownhere) comprising a coloring layer 1131 and a light-shielding layer(Black Matrix: BM) 1132 is provided.

Further, if each organic compound layer that can achieve R, G, and Bemission is formed selectively, a full color display can be obtainedwithout using a color filter.

A transparent protective layer 1117 is formed in order to seal thelight-emitting device 1118. The transparent protective layer 1117 may bepreferably formed of an insulating film containing silicon nitride orsilicon nitride oxide as its main components, which is formed bysputtering (DC type of RF type) or PCVD, a thin film containing carbonas its main component (for example, DLC film, or CN film), or alamination layer comprising the above. A silicon nitride film havinghigh blocking effects against impurity elements such as moisture, alkalimetals, or the like can be formed by using a silicon target under anatmosphere comprising nitrogen and argon. In addition, the transparentprotective film can be formed by a film formation system that usesremote plasma. It is preferable that the total thickness of thetransparent protective layer be formed to be thin as far as possible inorder that light may pass through the transparent protective layer.

Further, in order to seal the light-emitting device 1118, the sealingsubstrate 1104 is bonded to the substrate by the first sealing agent1105 and the second sealing agent 1107 under an inert gas atmosphere. Itis preferable to use such as an epoxy resin as a material for the firstsealing agent 1105 and the second sealing agent 1107. It is alsopreferable that the first sealing agent 1105 and the second sealingagent 1107 inhibit transmission of moisture or oxygen as possible.

Further, in this embodiment, a plastic substrate formed offiberglass-reinforced plastics (FRP), polyvinylfluoride (PVF) Mylar,polyester, an acrylic resin, or the like, in addition to a glasssubstrate or a quartz substrate can be used as a material whichconstitutes the sealing substrate 1104. It is possible that a thirdsealing material is applied to the side face (exposed face) of thesealing substrate and the substrate after bonding the sealing substrate1104 using the first sealant 1105 and the second sealant 1107.

By sealing the light-emitting device as described above, it becomespossible that the light-emitting device can be encapsulated completelyand penetration of moisture or oxygen from outside that causesdeterioration of the light-emitting device can be prevented.Consequently, light-emitting device having high reliability can beobtained.

Further, a both top and bottom emission light-emitting apparatus can beformed by using a transparent conductive film as the first electrode1113.

Further, this embodiment can freely be combined with any one ofEmbodiment Mode 1 to Embodiment Mode 3, or Embodiment 1.

Embodiment 3

In Embodiment 2, an example of the light-emitting apparatus structurethat has the light-emitting device in which an organic compound layer isformed over an anode and a cathode that is a transparent electrode isformed over the organic compound layer (hereinafter, “top emissionstructure”) was described. On the other hand, a light-emitting apparatusmay be formed to have the structure that has a light-emitting device inwhich an organic compound layer is formed over an anode and a cathode isformed over the organic compound layer (hereinafter referred to as“bottom emission structure”), and luminescence generated within theorganic compound layer emits in the direction of a TFT through the anodethat is a transparent electrode.

An example of a light-emitting apparatus having a bottom emissionstructure is shown in FIGS. 5A and 5B.

FIG. 5A is a top view of the light-emitting apparatus and FIG. 5B is across-sectional view of FIG. 5A taken along the line A-A′. Referencenumeral 1201 indicated by the dotted line denotes a source signal linedrive circuit; 1202 denotes a pixel portion; and 1203 denotes a gatesignal line drive circuit. Further, reference numeral 1204 is a sealingsubstrate; 1205 a is a sealing agent containing a gap material forspacing out enclosed spaces; and an inside area surrounded by thesealing agent 1205 a is filled with a sealing agent 1205 b. A desiccantmay be provided in the sealing agent 1205 b.

Reference number 1208 denotes a connection wiring for transmitting asignal to be inputted to the source signal line drive circuit 1201 andthe gate signal line drive circuit 1203. The connection wiring 1208receives a video signal or a clock signal from a flexible printedcircuit (FPC) 1209 which becomes an external input terminal.

Subsequently, a cross-sectional structure will be described withreference to FIG. 5B. A drive circuit and a pixel portion are formedover a substrate 1210, but the source signal line drive circuit 1201 asthe drive circuit and the pixel portion 1202 are shown in FIG. 5B. Thesource signal line drive circuit 1201 is formed of a CMOS circuit thatis a combination of an n-channel type TFT 1223 and a p-channel type TFT1224. These TFTs can be obtained according to Embodiment 1.

The pixel portion 1202 is formed from a plurality of pixels each ofwhich includes a switching TFT 1211, a current controlling TFT 1212, anda first electrode (anode) 1213 formed of a transparent conductive filmthat is electrically connected to a drain of the current controlling TFT1212.

In this embodiment, the first electrode 1213 is formed so as a part ofwhich to be overlapped with a connecting electrode so as to beelectrically connected to a drain region of the TFT 1212 via theconnecting electrode. It is preferable that the first electrode 1213 beformed of a conductive film that has transparency and a large workfunction (for example, an indium in oxide alloy (ITO), an indiumoxide-zinc oxide alloy (In₂O₃—ZnO), zinc oxide (ZnO), or the like).

Insulator 1214 (referred to as a bank, or the like) is formed to coverthe edge portion of the first electrode (anode) 1213. To improvecoverage, the upper edge portion or the lower edge portion of theinsulating substance 1214 b is formed to have a curved surface having acurvature. In addition, the insulator 1214 may be covered by aprotective film formed of an aluminum nitride film, an aluminum nitrideoxide film, a thin, film containing carbon as its main components, or asilicon nitride film.

An organic compound layer 1215 is selectively formed over the firstelectrode (anode) 1213 by vapor deposition using an evaporation mask orink-jetting. Further, a second electrode (cathode) 1216 is formed overthe organic compound layer 1215. As a material for forming the cathode,a small work function material (for example Al, Ag, Li, Ca, alloysthereof, that is, MgAg, MgIn, AlLi, CaF₂, or CaN) may be used. Thus, alight-emitting device 1218 comprising the first electrode (anode) 1213,the organic compound layer 1215, and the second electrode (cathode)1215, is fabricated. The light-emitting device 1218 emits light in thedirection indicated by an arrow in FIG. 9B. The light-emitting device1218 this embodiment is a type of the one which can achieve monochromeemission of R, G, or B. Full color emission can be achieved by thelight-emitting device in which each organic compound layer that canachieve R, G, and B emission is formed selectively.

Further, a protective layer 1217 is formed in order to seal thelight-emitting device 1218. The transparent protective layer 1217 may bepreferably formed of an insulating film containing silicon nitride orsilicon nitride oxide as it main components, which is formed bysputtering (DC type of RF type) or PCVD, a thin film containing carbonas its main component (for example, DLC film, or CN film), or alamination layer comprising the above. A silicon nitride film havinghigh blocking effects against impurity elements such as moisture, alkalimetals, or the like can be formed by using a silicon target under anatmosphere comprising nitrogen and argon. In addition, the transparentprotective film can be formed by a film formation system that usesremote plasma.

Further, order to seal the light-emitting device 1218, the sealingsubstrate 1204 is bonded to the substrate by sealing agents 1205 a and1205 b under an inert gas atmosphere. A depressed portion is formed overthe surface of the sealing substrate 1204 by sandblast in advance. Then,desiccant 1207 is placed to a depressed portion over the sealingsubstrate 1204. It is preferable to use an epoxy resin as the materialfor the sealing agents 1205 a and 1205 b. It is also preferable thatsealing agents 1205 a and 1205 b inhibit transmission of moisture oroxygen as possible.

In addition to a plastic substrate, a glass substrate, or a quartzsubstrate, a plastic substrate formed of polyester, acrylic, or thelike, can be used for the substrate 1210 in this embodiment.

Further, this embodiment can freely be combined with any one ofEmbodiment Mode 1 to Embodiment Mode 3, Embodiment 1, or Embodiment 2.

Embodiment 4

A cross-sectional structure of one pixel, especially a connection of alight-emitting device and a TFT, and a shape of a bank provided betweenpixels, will be described in this embodiment.

In FIG. 7A, reference numeral 40 denotes a substrate; 41, a bank; 42, aninsulating film; 43, a first electrode (anode); 44, an organic compoundlayer; 45, a second electrode (cathode); and 46, a TFT.

In the structure of TFT 46, reference numeral 46 a denotes a channelformation region; 46 b, 46 c, a source region or a drain region; 46 d, agate electrode; and 46 e, 45 f, a source electrode or a drain electrode.A top gate TFT is illustrated here, but not exclusively, a reversestaggered TFT or a forward staggered TFT may be utilized. In addition,reference numeral 46 f denotes an electrode that connects to the TFT 46by partly overlapping with the first electrode 43.

FIG. 7B is a cross-sectional view that is partly different from FIG. 7A.

in FIG. 7B, the first electrode and the source or drain electrode areformed to overlap each other in a different way from FIG. 7A. The firstelectrode is connected to the source or drain electrode by forming thefirst electrode to overlap the source or drain electrode after thepatterning process.

FIG. 7C is a cross-sectional view that is partly different from FIG. 7A.

In FIG. 7C, an interlayer insulating film is formed over the insulatingfilm 42. The first electrode 42 is connected to the electrode of the TFTthrough a contact hole.

The bank 41 may be formed to have a tapered shape in its cross-sectionalshape. The bank 41 can be formed into the tapered shape by exposing theresist by photolithography, and etching nonphotosensitive organic resinand inorganic insulating film.

The bank 41 can be formed into the shape of having a curved upper edgeportion as shown in FIG. 76 by using positive type photosensitive resinfor the bank 41.

The bank 41 can be formed into the shape of having a curved upper edgeportion and a curved bottom edge portion as shown in FIG. 7F by usingnegative type photosensitive resin for the bank 41.

This embodiment can be freely combined with any one of Embodiment Mode 1to Embodiment Mode 3, or Embodiment 1 to Embodiment 3.

Embodiment 5

By implementing the invention, various modules (active matrix typeliquid crystal module, active matrix type EL module and active matrixtype EC module) can be fabricated. That is, by implementing theinvention, all of the electric appliances incorporated those modules canbe completed.

As such electric appliances, a video camera, a digital camera, a headmount display (goggle type display), car navigation, a projector, a carstereo, a personal computer, a portable information terminal (a mobilecomputer, a cellular phone, an electronic book, or the like) or the likecan be given. FIGS. 8A to 9C show examples of these.

FIG. 8A is a personal computer which includes a main body 2001, an imageinput portion 2002, a display portion 2003, a keyboard 2004, or thelike. The personal computer can be formed to have high reliability andto be lightweight by using a plastic substrate having thermalconductivity according to the present invention for the module.

FIG. 8B is a video camera which includes a main body 2101, a displayportion 2102, a voice input portion 2103, an operation switch 2104, abattery 2105, an image receiving portion 2106, or the like. The videocamera can be formed to have high reliability and to be lightweight byusing a plastic substrate having thermal conductivity according to thepresent invention for the module.

FIG. 8C is a game machine which includes a main body 2201, an operationswitch 2204, a display portion 2205, or the like.

FIG. 8D is a player using a record medium recorded with programs(hereinafter, record medium) which includes a main body 2401, a displayportion 2402, a speaker portion 2403, a record medium 2404, an operationswitch 2405, or the like. Further, the player uses DVD (DigitalVersatile Disc) or CD as a record medium and can enjoy music, enjoymovie and carry out the game or Internet.

FIG. 8E is a digital camera which includes a main body 2501, a displayportion 2502, an eye-piece portion 2503, an operation switch 2504, animage receiving portion (not shown), or the like. The digital camera canbe formed to have high reliability and to be lightweight by using aplastic substrate having thermal conductivity according to the presentinvention for the module.

FIG. 9A is a cellular phone which includes a main body 2901, a voiceoutput portion 2902, a voice input portion 2903, a display portion 2904,an operation switch 2905, an antenna 2906, an image input portion (CCD,image sensor) 2907, or the like.

FIG. 9B is a portable book (electronic book) which includes a main body3001, display portions 3002, 3003, a record medium 3004, an operationswitch 3005, an antenna 3006, or the like. The portable book can beformed to have high reliability and to be lightweight by using a plasticsubstrate having thermal conductivity according to the present inventionfor the module.

FIG. 9C is a display which includes a main body 3101, a support base3102, a display portion 3103, or the like. The display can be formed tohave high reliability and to be lightweight by using a plastic substratehaving thermal conductivity according to the present invention for themodule.

Incidentally, the display shown in FIG. 9C is of a screen size of middleor small type or large type, for example, a screen size of 5 to 20inches. Further, in order to form the display portion of this size, itis preferable to use a display portion having a side of a substrate of 1m and carry out mass production by gang printing.

As described above, the range of applying the present invention isextremely wide and is applicable to a method of fabricating electricappliances of all fields. Further, the electric appliances of theembodiment can be realized by combining with any one of Embodiment Mode1 to Embodiment Mode 3, and Embodiment 1 to Embodiments 4.

Embodiment 6

The electric appliances represented in Embodiment 5 is installed with amodule that includes a panel having a sealed light emitting devicemounted with an IC including a controller and a circuit. Each of themodule and the panel can be thought as one mode of the light-emittingapparatus. In the present invention, a specific configuration of themodule will be described.

FIG. 10A shows an appearance of a module including a panel 1800 mountedwith a controller 1801 and a power supply circuit 1802. The panel 1800is provided with a pixel portion 1803 in which a light-emitting deviceis provided in each pixel, a gate line driver circuit 1804 for selectinga pixel in the pixel portion 1803, and a source line driver circuit 1805for supplying a video signal to the selected pixel.

The controller 1801 and the power supply circuit 1802 are provided in aprinted substrate 1806, various kinds of signals and power supplyvoltage output from the controller 1801 or the power supply circuit 1802are supplied via FPC 1807 to the pixel portion 1803, the gate linedriver circuit 1804, and the source line driver circuit 1805 in thepanel 1800.

The power supply voltage and the various kinds of signals are suppliedto the printed circuit 1806 via an interface (I/F) 1808 in which aplurality of input terminals are arranged.

Although the printed substrate 1806 is mounted on the panel 1800 withFPC in this embodiment, the present invention is tot limited to thisconfiguration. The controller 1801 and the power supply circuit 1802 maybe provided directly on the panel 1800 with COG (Chip on Glass) method.

Further, in the printed circuit 1806, there is a case that a capacitanceformed between leading wirings and a resistance of a wiring itself causea noise to a power supply voltage or a signal, or make a rise of asignal dull. Therefore, it may be provide various kinds of devices suchas a capacitor and a buffer to prevent the noise to the power supplyvoltage or a signal and the dull rise of the signal in the printedsubstrate 1806.

FIG. 10B is a block diagram showing the configuration of the printedsubstrate 1806. Various kinds of signals and power supply voltagesupplied to the interface 1808 are supplied to the controller 1801 andthe power supply circuit 1802.

The controller 1801 has an A/D converter 1809, a phase locked loop (PLL)1810, a control-signal generating portion 1811, and SRAMs (Static RandomAccess Memory) 1812 and 1813. Although the SRAM is used in thisembodiment, instead of the SRAM, SDRAM can be used and DRAM (DynamicRandom Access Memory) can also be used if it is possible to write in andread out data at high speed.

Video signals supplied via the interface 1808 are subjected to aparallel-serial conversion in the A/D converter 1809 to be input intothe control-signal generating portion 1811 as video signalscorresponding to respective colors of R, G, and B. Further, based onvarious kinds of signals supplied via the interface 1808, Hsync signal,Vsync signal, clock signal CLK, and volts alternating current (AC cont)are generated in the A/D converter 1809 to be input into the controlsignal generating portion 1811.

The phase-locked loop 1810 has a function to synchronize the phase ofthe frequency of each signal supplied through the interface 1808 withthe phase of the operating frequency of the control-signal generatingportion 1811. The operating frequency of the control-signal generatingportion 1811 is not necessarily the same as the frequency of each signalsupplied through the interface 1808, but adjust, in the phase-lockedloop 1810, the operating frequency of the control-signal generatingportion 1811 in a manner of synchronization with one another.

The video signal inputted to the control-signal generating portion 1811is once written into and held on the SRAMs 1812, 1813. Thecontrol-signal generating portion 1811 reads out the video signalscorresponding to all the pixels, one bit by one bit, from among all thebits of video signals held on the SRAM 1812, and supplies them to thesource line driver circuit 1805 in the panel 1800.

The control-signal generating portion 1811 supplies the informationconcerning a period during which the light emitting device of each bitcauses light emission, to the scanning-line driver circuit 1804 in thepanel 1800.

The power supply circuit 1802 supplies a predetermined power supplyvoltage to the source line driver circuit 1805, scanning-line drivercircuit 1804 and pixel portion 1803 in the panel 1800.

Explanation is now made on the configuration of the power supply circuit1802 with reference to FIG. 11. The power supply circuit 1802 of thisembodiment comprises a switching regulator 1854 using four switchingregulator controls 1860 and a series regulator 1855.

Generally, the switching regulator, which is small in size and light inweight as compared to the series regulator, can raise voltage and invertpolarities besides voltage reduction. On the other hand, the seriesregulator, which is used only in voltage reduction, has a well outputvoltage accuracy as compared to the switching regulator, hardly causingripples or noises. The power supply circuit 1802 of this embodiment usesa combination of the both.

The switching regulator 1854 shown in FIG. 11 has a switching regulatorcontrol (SWR) 1860, an attenuator (ATT) 1661, a transformer (T) 1862, aninductor (L) 1863, a reference power supply (Vref) 1864, an oscillatorcircuit (OSC) 1865, a diode 1866, a bipolar transistor 1867, a varistor1868 and a capacitance 1869.

When a voltage of an external Li-ion battery (3.6 V) or the like istransformed in the switching regulator 1854, a power supply voltage tobe supplied to a cathode and a power supply voltage to be supplied tothe switching regulator 1854 are generated.

The series regulator 1855 has a band-gap circuit (BG) an amplifier 1871,operational amplifiers 1872, a current source 1873, a varistor 1874, anda bipolar transistor 1875, and is supplied with a power supply voltagegenerated at the switching regulator 1854.

in the series regulator 1855, a power supply voltage generated by theswitching regulator 1854 is used to generate a direct current powersupply voltage to be supplied to a wiring (current supply line) forsupplying current to the anodes of various-color of light emittingdevices according to a constant voltage generated by the band-gapcircuit 1870.

Incidentally, the current source 1873 is used for a drive method towrite video signal current to a pixel. In this case, the currentgenerated by the current source 1873 is supplied to the source linedriver circuit 1805 in the panel 1800. In the case of a drive method towrite the video signal voltage to a pixel, the current source 1873 neednot necessarily be provided.

A switching regulator, an OSC, an amplifier and an operation amplifiercan be formed using TFT.

The structure of this embodiment may be freely combined with any ofEmbodiment Mode 1 to 3 and Embodiment 1 to 5.

Embodiment 7

An example of a fabricating method for a passive matrix light-emittingapparatus (also referred to as a simple matrix light-emitting apparatus)will be described in this embodiment.

A metal film (typically, a tungsten film) is formed over a glasssubstrate, and an oxide layer (typically, an oxide silicon film) isformed over the metal film, then, plural first wirings are formed intostriped form over the oxide layer using a material such as ITO (amaterial to be an anode). Next, a bank formed of resist orphotosensitive resin is formed so as to encircle a region to be alight-emitting region. Then, a layer containing an organic compound isfabricated in the region that is encircled by the bank by vapordeposition or ink-jetting. In the case of achieving a full colordisplay, a layer containing an organic compound is fabricated byselecting, appropriately materials. Striped plural second wirings areformed of a metal material such as Al or an alloy of Al (a material tobe a cathode) over the bank and the layer containing an organic compoundso as to intersect with the plural first wirings formed of ITO.According to above-described processes, a light-emitting device using alayer containing an organic compound as a light-emitting layer can befabricated.

Then, a sealing substrate is bonded to the glass substrate, or aprotective film is formed over the second wiring so as to seal thelight-emitting device. As suitable materials for a sealing substrate,mixture of a low-melting metal (lead-free solders such as tin, bismuth,and zinc); ceramics such as boron nitride, aluminum nitride, magnesiumoxide, beryllium nitride, or the like; and synthetic-resin composed ofpolypropylene, polypropylene sulfide, polycarbonate, polyetherimide,polyphenylene sulfide, polyphenylene oxide, polysulfone, orpolyphthalamide having high thermal conductivity ranging from 2 to 30W/mK is useful.

Then, a glass substrate is peeled-off. The internal or the interface ofthe oxide layer can be peeled-off by a physical means. Thereafter, aplastic substrate that is transparent to light is bonded thereto with anadhesive.

FIG. 12A is a view showing the example of a cross-sectional structure ofa display device according to the present invention.

The pixel portion 201 is provided in which a first electrode and asecond electrode are formed to intersect each other via an adhesive 152over the main surface of a plastic substrate 100 having high thermalconductivity, and a light-emitting device is fabricated over theintersection of the first and second electrodes. That is, the pixelportion 201 comprising luminescent pixels formed in a matrixconfiguration is formed. The number of pixels are 640×480 dots in thecase of VGA, 1024×768 dots in the case of XGA, 1365×1024 dots in thecase of SXGA, and 1600×12.00 dots in the case of UXGA. The number of thefirst electrode and the second electrode is determined depending on thenumber of the pixels. Moreover, an input terminal portion provided witha terminal pad for connecting with an external circuit is formed at theedge portion of the substrate 101, the periphery portion of the pixelportion 201.

In the display device shown in FIG. 12A, the pixel portion in which thefirst electrode 102 that extends in the directions of both right andleft is formed on the main surface of the substrate 100 via the adhesive152, and a thin film 105 including a luminous body (hereinafter referredto as an EL layer as a matter of convenience since the thin filmincludes medium that exhibits electroluminescence) is formed thereon,then, the second electrode 106 that extends in the directions of bothtop and bottom is formed thereon, and then, a pixel is formed over theintersection of the first and second electrodes is formed. That is,pixels are arranged in a matrix configuration by forming the firstelectrode 102 and second electrode 106 in the lengthwise andbreadthwise. The input terminal is formed of the same material as thatfor forming the first electrode and the second electrode. The number ofthe input terminals is the same as that of the first electrodes and thesecond electrodes arranged in the lengthwise and breadthwise.

As seen from the cross-sectional form of the bank 104, areas from thebottom end portion, which is in contact with the first electrode, to thetop end portion has a curved surface. The curved surface form of thebank 104 has at least one radius of curvature having a center of thecurvature in the bank or at the bottom end portion of the bank. Or thecurved bottom end portion, which is in contact with the first electrode102, of the bank 104 has at least one first radius of curvature having acenter of the curvature at the outside of the bank 104, and the curvedupper end portion of the bank 104 has at least one second radius ofcurvature having a center of the curvature in the bank or at the bottomend portion side. The cross-sectional form of the bank 104 may have acontinuous variable radius of curvature at the areas from the bottom endportion to the upper end portion. An EL layer is formed along the curvedsurface form. The curved surface form makes the stress of the EL layerrelax. That is, the curved surface form is possible to reduce thedistortion due to the thermal stress of a light emitting device formedof a stacked layer of different materials.

A opposing substrate 150 for sealing a pixel portion 201 is firmly fixedwith a sealing agent 141. The space between the substrate 101 and theopposing substrate 150 may be filled with inert gas or sealed an organicresin material 140 therein. In any event, a light-emitting device in thepixel portion 201 can prevent its deterioration due to extrinsicimpurities without providing drying agent since the light-emittingdevice is coated with a barrier insulating film 107.

As shown in FIG. 12A, coloring layers 142 to 144 are formed at the sideof the opposing substrate 150 corresponding to each pixel of the pixelportion 201. A flattening layer 145 can prevent unevenness due to thecoloring layers. FIG. 12B is a view showing a structure in which thecoloring layers are formed at the side of the substrate 101, and thefirst electrode 102 is formed over the flattening layer 145. Thesubstrate 101 is bonded to the flattening layer 145 with an adhesive153. The opposing substrate 151 has high thermal conductivity. The lightemitting direction in the structure shown in FIG. 12B is different fromthat shown in FIG. 12B. In FIG. 12A, like components are denoted by likenumerals as of FIG. 12B.

The present invention can be applied not only to a full color displaydevice but also a surface luminous, electric spectaculars device, or thelike.

This embodiment can be freely applied to any one of Embodiment Modes 1to 3, or Embodiment 5.

According to the present invention, heat generated from a device isradiated through a plastic substrate having a high thermal conductivityto increase life of the device and to improve reliability of asemiconductor device.

Further, the plastic substrate having a high thermal conductivity isinexpensive and flexible and light-weight as compared with a metalsubstrate.

1. (canceled)
 2. A light emitting display device comprising: a first substrate being flexible; a first electrode over the first substrate; an EL layer over the first electrode; a second electrode over the EL layer; a second substrate over the second electrode, a color filter between the first substrate and the second substrate; a first sealing material; and a second sealing material between the first substrate and the second substrate, wherein the first sealing material is provided outside the second sealing material, and the first sealing material is covering side faces of both the first substrate and the second substrate.
 3. The light emitting display device according to claim 2, wherein the color filter is over the second electrode.
 4. The light emitting display device according to claim 2, further comprising a third sealing material, wherein the third sealing material is provided inside the first sealing material.
 5. The light emitting display device according to claim 2, wherein the second substrate is flexible.
 6. The light emitting display device according to claim 2, further comprising a transistor between the first substrate and the second substrate, wherein one of a source and a drain of the transistor is electrically connected to the first electrode.
 7. The light emitting display device according to claim 2, wherein the EL layer emits white light.
 8. The light emitting display device according to claim 2, wherein the second electrode is a lamination of a metal film and a transparent conductive film, wherein the metal film comprises a material selected from the group consisting of Al, Ag, Li, Ca, MgAg, MgIn, AlLi, CaF₂, and CaN, and wherein the transparent conductive film is selected from the group consisting of indium oxide-tin oxide alloy, indium oxide-zinc oxide alloy and zinc oxide.
 9. A light emitting display device comprising: a first substrate being flexible; a first adhesive over the first substrate; a first electrode over the first adhesive; an EL layer over the first electrode; a second electrode over the EL layer; a second substrate over the second electrode; a color filter between the first substrate and the second substrate; and a sealing material, wherein the sealing material is provided outside the first adhesive, and the sealing material is covering side faces of both the first substrate and the second substrate.
 10. The light emitting display device according to claim 9, wherein the color filter is over the second electrode.
 11. The light emitting display device according to claim 9, further comprising a second adhesive between the first substrate and the second substrate, wherein the second adhesive comprises two sealing materials, and wherein one of the two sealing materials is provided inside the another of the two sealing materials.
 12. The light emitting display device according to claim 9, wherein the second substrate is flexible.
 13. The light emitting display device according to claim 9, further comprising a transistor between the first substrate and the second substrate, wherein one of a source and a drain of the transistor is electrically connected to the first electrode.
 14. The light emitting display device according to claim 9, wherein the EL layer emits white light.
 15. The light emitting display device according to claim 9, wherein the second electrode is a lamination of a metal film and a transparent conductive film, wherein the metal film comprises a material selected from the group consisting of Al, Ag, Li, Ca, MgAg, MgIn, AlLi, CaF₂, and CaN, and wherein the transparent conductive film is selected from the group consisting of indium oxide-tin oxide alloy, indium oxide-zinc oxide alloy and zinc oxide. 